A364429 a(0) = 1, a(n) = (2*n^5 + 20*n^3 + 23*n) * 2/15 for n>=1.
1, 6, 36, 146, 456, 1182, 2668, 5418, 10128, 17718, 29364, 46530, 71000, 104910, 150780, 211546, 290592, 391782, 519492, 678642, 874728, 1113854, 1402764, 1748874, 2160304, 2645910, 3215316, 3878946, 4648056, 5534766, 6552092, 7713978, 9035328, 10532038, 12221028
Offset: 0
Examples
a(3) = 146 since the 6th octahedral number is 146; A005900(6) = 146. a(4) = 456 since the 6th 16-cell number is 456; A014820(5) = 456.
Links
- OEIS Wiki, Orthoplex numbers.
- Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).
Crossrefs
Programs
-
Mathematica
Prepend[Table[2/15 (2 x^5 + 20 x^3 + 23 x), {x, 100}], 1] -
Python
print([1]+[(2*i**5+20*i**3+23*i)*2//15 for i in range(1,101)])
Formula
a(0) = 1, a(n) = (2*n^5 + 20*n^3 + 23*n) * 2/15 for n>=1.
G.f.: (1 + 15*x^2 + 15*x^4 + x^6)/(1 - x)^6. - Stefano Spezia, Jul 24 2023
Comments